Ocular albinism type 1

What causes ocular albinism type 1?

Ocular albinism type 1 is caused by mutations in the GPR143 _gene. This gene gives the body instructions for making a protein that plays a role in pigmentation (coloring) of the eyes and skin. It helps control the growth of melanosomes, which are structures inside cells that make and store a pigment called melanin. Melanin also plays a role in vision in the retina. Mutations in the _GPR143 gene can affect the protein's ability to do its job. As a result, melanosomes in skin and retinal cells can grow abnormally large, contributing to the signs and symptoms of the condition. In rare cases, the genetic cause of this condition is unknown.

Last updated on 05-01-20

I am a female with ocular albinism type 1 and I'm pregnant. Are my children at risk for inheriting this condition?

We understand your desire to learn more about ocular albinism type 1 and what it may mean for your current and future pregnancies. To know with certainty your chances of having a baby with this condition, we recommend that you speak with a genetics professional. Ocular albinism type 1 is usually inherited in an X-linked recessive fashion. Usually, the sons of a woman with ocular albinism will each have the condition and her daughters will all be carriers for the condition. However, this is not always the case depending on the reason why a woman is affected.

We strongly recommend you discuss your concerns with a genetics professional A genetics professional will try to determine why you are affected and what the underlying cause of your condition is first. This information will be important in estimating your recurrence risk. Genetic professionals are a source of information for individuals and families regarding genetic diagnosis, natural history, treatment, mode of inheritance, and genetic risks to other family members. To find a genetics clinic, we recommend that you contact your primary doctor for a referral. Click here to learn more about genetic consultations.

The following online resources can also help you find a genetics professional in your community:

The National Society of Genetic Counselors provides a searchable directory of US and international genetic counseling services.

The American College of Medical Genetics has a searchable database of US genetics clinics.

The University of Kansas Medical Center provides a list of US and international genetic centers, clinics, and departments.

The American Society of Human Genetics maintains a database of its members, which includes individuals who live outside of the United States. Visit the link to obtain a list of the geneticists in your country, some of whom may be researchers that do not provide medical care.

Last updated on 05-01-20

How is ocular albinism type 1 inherited? Are males or females more likely to be affected?

Ocular albinism type 1 is usually caused by mutations in the GPR143 gene. In these cases, the condition is inherited in an X-linked recessive manner. Males are more commonly affected than females. This is because males have only one X chromosome and therefore one copy of the GPR143 gene. Females have two X chromosomes and therefore two copies of the GPR143 gene. If females have a mutation in one of their GPR143 genes, they still have a second normal GPR143 gene to compensate. Women with one mutated copy of the gene usually do not have vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination.

Occasionally, females will have more significant signs and symptoms of ocular albinism type 1. This may be due to:

Last updated on 05-01-20

Do people with ocular albinism type 1 have learning disabilities?

Ocular albinism type 1 (OA1) is not associated with learning disabilities. People with OA1 typically have normal development and intelligence. Reduced visual acuity can result in difficulty in school, so measures may be taken to improve functioning in school (such as having appropriate visual aids, requesting large-print books and handouts, and sitting in the front of the classroom).

Last updated on 05-01-20

What is ocular albinism type 1?

Ocular albinism type 1 (OA1) is a genetic eye condition that primarily affects males. Signs and symptoms may include reduced coloring of the iris and retina (ocular hypopigmentation); foveal hypoplasia (underdevelopment); rapid, involuntary eye movements (nystagmus); poor vision; poor depth perception; eyes that do not look in the same direction (strabismus); and increased sensitivity to light. It is caused by mutations in the GPR143 gene and is inherited in an X-linked recessive manner. Females have been affected in rare instances. Treatment consists of visual correction with eyeglasses or contact lenses; use of sunglasses or special filter glasses for light sensitivity; and in some cases, extraocular muscle surgery to restore alignment and/or improve head posture that is associated with nystagmus.

Last updated on 05-01-20

Does ocular albinism type 1 affect night vision?

To our knowledge, ocular albinism type 1 (OA1) does not specifically affect night vision. The condition causes reduced visual acuity in general, in addition to various other ocular features. Another condition called congenital stationary night blindness, which is part of the differential diagnosis of OA1 and has some overlapping features, has night blindness as a feature.

Last updated on 05-01-20

Can people with ocular albinism type 1 drive?

The reduced visual acuity in people with ocular albinism type 1 (OA1) can limit the ability to obtain a driver's license because most states require at least 20/70 vision (best corrected with glasses or contact lenses) to obtain at least a daylight-restricted driver's license. However, requirements vary by country and by state. In some cases, drivers may be required to use bioptics. The National Organization for Albinism and Hypopigmentation provides useful information about albinism and driving.

Last updated on 05-01-20

What is the long-term outlook for people with ocular albinism type 1?

Ocular albinism type 1 (OA1) a non-progressive disorder. Visual acuity typically remains stable throughout life, even often slowly improving into the mid-teens. Although nystagmus usually develops within the first 3 months of life, it can diminish with time. However, it rarely completely disappears. Because the specific ocular signs and symptoms in affected people can vary, the condition may cause some people to be more visually impaired than others. People with OA1 have a normal life expectancy.

Last updated on 05-01-20

How might ocular albinism type 1 be treated?

Hypersensitivity to light, often called "photoaversion," "photophobia," or "photodysphoria," is the most incapacitating symptom in some people with ocular albinism type 1 (OA1). This symptom may be relieved by sunglasses, transition lenses, or special filter glasses, although many prefer not to wear them because of the reduction in vision from the dark lenses when indoors.

Refractive errors should be detected and treated as early as possible with appropriate spectacle correction. Abnormal head posture may be treated with prismatic spectacle correction.

Strabismus surgery is usually not necessary but may be performed for cosmetic purposes, particularly if the strabismus or the face turn is marked or fixed.

Appropriate education for sun-protective lotions and clothing (preferably by an informed dermatologic consultant) is recommended to moderate the lifelong effects of sun exposure.

Children with ocular albinism who are younger than 16 years of age should have an annual ophthalmologic exam (including assessment of refractive error and the need for filter glasses), as well as psychosocial and educational support. Affected adults should have ophthalmologic exams when needed, typically every two to three years.

Last updated on 05-01-20

Name: Prevent Blindness America 211 West Wacker Drive, Suite 1700
Chicago, IL, 60606 , United States
Toll Free: 800-331-2020 Email: info@preventblindness.org Url: http://www.preventblindness.org/
Name: National Alliance for Eye and Vision Research (NAEVR) 1801 Rockville Pike, Suite 400
Rockville, MD, 20852, United States
Phone: 240-221-2905 Fax : 240-221-0370 Email: jamesj@eyeresearch.org Url: http://www.eyeresearch.org/
Name: The National Organization of Albinism and Hypopigmentation (NOAH) PO Box 959
East Hampstead, NH, 03826-0959 , United States
Phone: 603-887-2310 Toll Free: 800-473-2310; Email: noah@albinism.org Url: http://www.albinism.org
Name: Vision of Children Foundation (VOC) 12671 High Bluff Drive, Suite 300
San Diego, CA, 92130 , United States
Phone: 858-799-0810 Fax : 858-794-2348 Email: cdenofrio@visionofchildren.org Url: http://www.visionofchildren.org

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